Typically yarns are typically produced by spinning fibers of wool, flex, cotton or other materials to achieve long strands which shall be called yarns or threads. Particularly, the yarn according to the present disclosure shall be used for manufacturing textiles or fabrics, particularly jean fabric, denim or dungaree. In order to provide an elastically stretchable yarn, it is known to integrate in yarns a filamentary core consisting of one or more elastic performance filaments. A yarn is a strand of a long continuous length provided on bobbins. Usually the outside of the yarn, i.e. a sheath or coat, is realized by interlocked fibers, particularly of cotton.
WO 2008/130563 A1 discloses an elastic composite yarn consisting of a filamentary core having at least one such elastic performance filament and one inelastic control filament. Said filamentary core is surrounded by a fibrous sheath of spun-stable fibers. According to the embodiment of FIGS. 2 and 3 of WO 2008/130563 A1 the filamentary core comprises both one elastic performance filament and one inelastic control filament.
Further, from WO 2012/062480 A2 a composite stretch yarn is known comprising a filament core and a fibrous sheath surrounding the filamentary core and being made of cotton fibers. The filamentary core is realized by one elastic performance filament and one inelastic control filament. Said inelastic control filament can be a PTT/PET bicomponent elastomultiester or the like as disclosed in EP 1 846 602.
The inventor of this present disclosure found out that above-mentioned conventional elastic yarns used for manufacturing textile material like a denim fabric, suffer from a non-sufficient elastic behavior, as recovery. Elastic recovery is an important property for an elastic yarn in that the yarn is capable of regaining its original length after deformation by first applying tensile stress and further releasing said stress. If the recovery properties of the elastic yarn are not sufficient or too low, an undesired growth effect may arise. The growth effect is undesired because the elastic yarn does not provide enough elastic recovery in order to bring back the elastic yarn to its original condition before the stress was applied. Considering microscopically a fabric product, particularly trousers made of a fabric woven on the basis of elastic yarns, in highly stressed textile fabrics, as the area of knees and back a the trousers, the growth effect causes an inappropriate slaggy fit which could even make the textile product useless for the consumer. However, if the fabric as such is designed of having a stronger elastic recovery, such fabric would provide a more uncomfortable fit for the consumer particularly at areas, e.g. at arm or leg sleeves, which do not suffer the same stress peaks as at knees and back portion. This undesired, tight fit is known as “corset”-phenomenon.
The exemplary embodiments of the present disclosure will be described with reference to the accompanying drawings.